Multiple range power transmission mechanism



United States Patent [72] Inventors William .l.Foxwell References Cited5X55XX4XX33 33333363335 /3//5336332 2322/3M33M9 9/992/7//71 141194 44 717 77 S m m m m m m m T m N E m T m A P L m m mm m m Nnnuuue u n T n. mmum rm n marmi m e s mnmmwmm .l o I uw CKKBHFMEFGm n 36791345578 N55556666666 U 99999999999 lllllllllll 87964595732 l 6832368483192478398872 Llv-JnvwdvOV-JDOJ 73508894289 45097848901.. ,JDoOV'MJI-vn22222333333 n a .m .n m t M m m u V. W M mnh 9 a@ S pgn m mmf 0 0 0sockn L 07u-M 990 m F 11MB" l i r N184 nanzzmmm y mmnnwwu TW70NFDa a deN. m m Mmmm. .pnMaS AFPA .l.l.l.l 1253 2247 .l.l.l.l

Primary Examiner-Arthur T. McKeon Attorneys-John R. Faulkner and DonaldJ. Harrington 333; l92/3.5, 5 3.6 sped ratios in the operating ranges.

Sheet INVENTORS.-

GENERAL DESCRIPTION oF THE INVENTION The improved transmission mechanismof our invention is adapted to be used in the driveline of agriculturaland industrial tractors as well as certain types of heavy trucks andconstruction vehicles. It includes stepped ratio gearing having acountershaft and a main torque'delivery shaft. Main transmission speedratio gears, which establish the various torque delivery paths, are.mounted for rotation about the axis of the main shaft. Thesecontinuously engage gear elements mounted on thecountershaft. Byengaging and disengaging the elements of the main gearing with respectto the main torque delivery shaft, ratio changes can be accomplished.

The disposition of the elements of the main transmission gearing and theelements of the countershaft gearing is such that synchronizer clutchelements and power shift clutch elements can be used interchangeablywithout altering either the gearing arrangement or the transmissionhousing for the gearing. Regardless of whether the synchronizer clutchesor power shift clutches are used to establish ratio changes, the rangeselector gearing cooperates with the speed ratio change gear- Ing. i

Multiple ratio changs are available for each of the selected operatingranges. We have shown separate embodiments, one having syrichronizer,clutches and the other having disc clutches with a fluidf pressureoperated servo for establishing and disestablishing clutch engagement.In the latter, a control valve for the servos is under the control ofthe vehicle operator.

If it Ais desired to eliminate the synchronizer clutches and theservooperated power shift disc clutches, they can be replaced bymanually Operated dog clutches if ratio changes within each operatingrange` are not desired while the vehicle is in motion. In this case,ratio changes can be accomplished only when the vehicle is stopped. Thisalternate arrangement also has been disclosed in the specification.

" BRIEF DESCRIPTION OF THE FIGURES F THE DRAWINGS FIG. l shows inlongitudinal cross section form transmission assembly embodyingimprovements in my invention wherein ratio changes are accomplished bymeans of synchronizer clutches,

FIG. 2 is a longitudinal cross-sectional view of a transmission similarto the structure of FIG. l, although the synchronizer clutches have beenreplaced by servo operated disc clutches.

FIG. 3 is a longitudinal cross-sectional view of an alternatetransmission mechanism embodying features that are common to thestructures'of FIGS. 1 and 2 although the synchronizer clutches and thepower shift clutches of FIGS. 1 and 2 have been replaced by manuallyoperated dog clutches.

e PARTICULAR DESCRIPTION OF THE INVENTION Numeral l'designatesatra'nsmission housing having a .main clutch portion 12 and a main gearportion 14. The housing 12 is provided with a bolt flange 16 which maybe bolt'edrto the engine block of an engine such as a compressionignition engine in an agricultural or industrial tractor vehicledriveline.

The engine includes a crankshaft which is bolted by means of bolts 18 tothe center of a flywheel 20. The hub of the flywheel shown at 22 issplined at 24 to a power takeoff shaft 26 which extends axially throughthe transmission assembly. It is supported at its right-hand end, asshown in FIG. l, by means of a bearing 28 received within a bearingopening 30 formedin a bearing support plate 32. This plate is bolted bybolts 34 to an endflang'e 36 formed on housing portion 14. The shaft 26is splined at 38 to permit a driving connection with suitable auxiliaryequipment with which the tractor is used.

vided with an internal sleeve 46 which supports a clutch' throwoutbearing 44. The bearing 44 is slidably positioned on a stationary sleeveshaft 46 carried by the support plate 40. .Iournaled inside the sleeveshaft 46 is a clutch output shaft 48 which is supported by bearing 50located in the hub 22 of the flywheel. Shaft 48 is splined at 5l topermit a driving engagement between a friction disc neutral clutch,shown in dotted lines, which would be situated within the housingportion 12. The clutch structure includes a friction disc 51 whichengages friction surface 52 on flywheel 20 when the clutch is engaged,thereby establishing a driving connection between the crankshaft and thesleeve shaft 48.

A conventional clutch operating lever 54 is mounted in the housingportion 12 for oscillation about an axis 56. The operating end 58 of thelever 54 disengages the bearing 44 so that the latter can be adjustedaxially along the support sleeve shaft 46. As the bearing 44 is shiftedin a left-hand direction, it engages clutch release levers that causethe friction disc to be disengaged from the flywheel. As bearing 44 isshifted in a right-hand direction, clutch springs in the clutch assemblyengage the friction disc against the flywheel surface 52.

A transmission main shaft is shown at 60. It is journaled at itsleft-hand end by bearing 62 supported by the plate 40. The left-hand endof the shaft 60 is splined at 64 to the right-hand end of the clutchoutput shaft 48.

A transmission center support 66 is located within the housing portion14 and forms a part thereof. It is formed with a bearing opening 68 inwhich is positioned a support bearing 70. This journals rotatably apower output gear 72. The righthand end shaft 60 is journaled within acentral opening in the gear 72 by means of bearing assembly 74.

Another main gear 76 is journaled on the main shaft 60 by means of abushing. It is formed with clutch element 78 having external clutchteeth. In similar fashion gear 72 is formed with clutch element 80having external clutch teeth. The synchronizer clutch hub 82 is splinedat 84 to the shaft 60. A

v clutch sleeve 86 is slidably positioned on the hub 82. It may be movedin either axial direction into meshing engagement with a clutch element78 or the clutch element 80, thereby establishing a driving connectionbetween shaft 60 and the gears 76 and 72, respectively.

An internal cone clutch element 88 is drivably connected to the externalteeth of the clutch element 80, and a corresponding cone clutch element90 is drivably connected to the external teeth of clutch element 78. Theclutch elements 88 and 90 are situated in juxtaposition, and they eachare adapted to register with the external cone clutch surfaces of clutchelements 92 and 94, respectively. A series of solid and bipartitesynchronizer pins 96 carries the clutch elements 94 and 92 at theiropposite ends, thereby forming a unitary, shiftable, clutch assembly.Shifting movement of this assembly is effected by the lost motionconnection between the sleeves 86 and the pins 96. The pins 96 areformed with a groove 98 which registers with a surrounding shoulder suchas that shown-at 100 formed in openings in the sleeve 86. The Outermargin ofthe sleeve 86 is formed with a groove which receives the armsof the shift fork assembly 102.

I-Ialf of the pins 96 are bipartite in form, each part being urged intoengagement with the shoulder 100 in its cooperating opening by means ofa leaf spring 104 located internally as indicated in FIG. 1.

As the sleeve 86 is shifted in a left-hand direction, the detent actionestablished by the unyieldable shoulder 100 of the solid pins 96 urgethe clutch element 94 into clutching engagement with clutch element 90thereby tending to establish synchronism between the motion of the shaft60 and the motion of the gear 76. After synchronism is established, thesleeve 86 is shifted in its left-hand direction so that the internalteeth of the sleeve 86 engage the external teeth of the clutch element78 without clashing.

va detent force that causes the clutch element 92 to frictionally engagethe clutch element 88, thereby establishing synchronism between themotion of the shaft 60 and the motion of the gear 72 prior to clutchingengagement of the teeth of the sleeve 86 with the external teeth of theclutch element 80.

A third main torque transmitting gear 106 is journaled also on the shaft60. A power input gear 108 also is journaled on the shaft 60 in spacedrelationship with respect to the gear 106. Gear 106 is formed with aclutch element 110 having external clutch teeth, and gear 108 is formedwith a corresponding clutch element 112 also having external teeth.Synchronizer clutch hub 114 is splined to the shaft 60.

A hub 114 forms a part of a Synchronizer clutch assembly that includesalso cone clutch elements 116 and 118 which establish synchronism in themotion of the shaft 60 with respect to the motion of the gear 108. Itincludes also cone clutch elements 120 and 122 which establishsynchronism in the motion of the shaft 60 with respect to the motion ofthe gear 106 as the gear 106 is connected to the shaft 60.

The clutch elements 116 and 120 are carried by a set of solid andbipartite Synchronizer pins 124 which extend through the aperturesformed in the clutch sleeve 126. The arms of the shift fork 128 engagean annular groove formed in the margin of the sleeve 126. Sleeve 126 isformed with internal clutch teeth slidably positioned on the externalteeth of the hub 114. The sleeve teeth engage the clutch elements 110 or112, depending upon the direction in which it is shifted.

Another internal bearing support wall 130 is provided with a bearingopening that receives bearing assembly 132. This journals rotatably afirst main gear 134. Shown integrally with the main gear 134 is thesmaller pitch diameter main gear 136, which is journaled by means ofbearing 138 in a bearing opening formed in bearing support plate 32. Asleeve shaft 140 is connected to gear 134 and 136 surrounding the powertakeoff shaft 26.

The clutch hub 142 is splined to the shaft 140. It is formed withinternal teeth which register with the external teeth of clutch sleeve144. Situated between the hub 142 and the bearing 132 is a reverse gear146. It is journaled on the shaft 140, and it carries external clutchteeth 148 situated directly adjacent the external teeth of the hub 142.Other external clutch teeth 150 are carried by the gear 72. The teeth150 and 148 are adapted to engage the internal teeth of the sleeve 144as the latter is shifted in one direction or the other, therebyestablishing selectively a driving connection between the shaft 140 andthe gears 72 and 146. The sleeve 144 is provided with a peripheralgroove 152 which receives the arms of the shift fork, not shown.

A countershaft 154 is mounted rotatably in the transmission housingportion 14 in parallel disposition with respect to main shaft 60.Shaft-154 is journaled by a bearing 156 received in a bearing openingformed in the bearing support wall 130. The latter forms a part of thehousing 14. The left-hand end of the shaft 154 is journaled by means ofbearing 158 in a bearing opening formed in the bearing support wall 40.A plurality of external gear elements of decreasing pitch diameter issupported by the shaft 154 and is splined thereto for rotation inunison. A first countershaft gear 160, which is splined to the shaft 154at 162, drivably engages the gear 108.` The second and thirdcountershaft gears 164 and 166 are formed in a cluster, and they aresplined at 168 to the shaft 154. These gears engage respectively themain gears 106 and 76.

A fourth countershaft gear 170 engages drivably the main gear 72. Itforms a part of a cluster which includes also reverse gear 172, thelatter engaging a reverse drive pinion 174 which vin turn engages thegear 146. Gears 170 and 172 are splined to the shaft 154 at 173.

An output drive assembly is situated at the rearmost end of thetransmission mechanism. lt includes a power output shaft 176 whichcarries an output gear 178 which in turn drivably meshes with gear 13'6.Shaft 176 and gear 178 are journaled by bearing 180 in a bearing openingformed in support plate 182. This in turn is bolted to the bearingsupport plate 32.

A gear mounting shaft 184 is received within an end opening 186 formedin shaft 154 and is journaled therein by bearing 188.

The right-hand end of the shaft 154 rotatably journals output gear 190.This meshes directly with gear134. Situated directly adjacent the gear190 is a clutch hub 192 having external teeth which engage internalteeth of clutch sleeve 194. External clutch teeth 196 are carried by thegear 190 directly adjacent the external teeth of the hub 192. ln asimilar fashion external teeth 198 are carried by the gear 178 directlyadjacent the external teeth of the hub 192. The teeth 196 and 198 areengaged selectively by the teeth of the sleeve 194 as the latter isshifted in one direction or the other.

The mechanism shown in FIG. 1 is capable of establishing threeforward-drive operating ranges. These may be identified as the transportrange, the range of high speed ratios which may be used when the vehicleis operating with minimum resistance, a field operating range which isused when the vehi cle is operating with a normal resistance, and acreeper operating range for use when resistance is unusually high.

To establish the field operating range, sleeve 144 is shifted in aleft-hand direction into engagement with teeth 150. This establishes adriving connection between gear 72 and shaft 140. Having chosen thefield operating range, the operator then can select any one of fourration shifts. The first ratio which produces maximum torquemultiplication in that operating range is achieved by shifting theSynchronizer clutch sleeve 126 in a left-hand direction, therebyestablishing a driving connection between the clutch output shaft 48 andgear 108.

To establish field operation, sleeve 144 is shifted in a lefthanddirection. The operator then can use the Synchronizer clutches toestablish various ratio changes. The first speed ratio in the fieldrange is achieved by shifting clutch sleeve 126 in a left-hand directionthereby locking the shaft 60 to the gear 108. Torque is delivered thenfrom shaft 48 to the gear 108, to the gear 160, through the countershaft154 to the gear 170, through the gear 72, through the clutch sleeve 144,and through gears 136 and 178 to the shaft 176.

A synchronized ratio shift to the second speed ratio can be achieved byshifting sleeve 126 in a right-hand direction, thereby locking shaft 60to the gear 106. Torque then is delivered to the countershaft 154through the gears 106 and 164, rather than through the gears 108 and160, thereby establishing an increased speed ratio.

The third speed ratio operation is achieved by shifting the Synchronizerclutch sleeve 86 in a left-hand direction and returning the sleeve 126to the neutral position shown in FIG. 1. Shaft 60 then becomes locked togear 76. Torque is delivered, therefore, from the shaft 48 and throughthe gears 76 and 166 to the countershaft 154.

A shift to the fourth speed ratio is achieved by shifting theSynchronizer clutch sleeve 86 in a right-hand direction,

thereby locking the gear 72 to the shaft 60. Torque from the l shaft 60then is delivered through the shaft 80 and through the gears 72 and 170to the countershaft 154.

Reverse drive is achieved by shifting the sleeve 144 in a right-handdirection, thereby locking the reverse gear 146 to the shaft 140. Astorque is delivered to the countershaft 154 through the torque flowpattern described previously, reverse gear 172 is driven. This causes acounter rotation of the gear 146 because of the reversing motionimparted to it by the pinion 174. Gear 136 and gear 178 then drive theshaft 176 in a reverse direction.

A so-called Creeper-drive ratio is achieved by moving the sleeve 144 tothe neutral position shown in FIG. 1, thereby moving sleeve 194 in aleft-hand direction, thus locking the gear 190 to the countershaft 154.The torque imparted to the countershaft 154 through the torque flowpattern described previously then is multiplied by the two pairs ofgears shown at 190 and 134 and at 136 vand 178, thus driving the shaft176 at a reduced relative speed. All of the ratio shifts describedpreviously can be accomplished while the final drive gearing is in theCreeper-drive condition.

A so-called high-speed ratio transport condition is achieved by shiftingthe sleeve 194 in a right-hand direction, thereby Gears 134 and 13 6freewheel under these conditions.

In the embodiment shown in FIG. 2, the synchronizer clutch assemblieshave been replaced by servo pressure operated disc clutches. In otherrespects the structure of FIG. 2 is the same as the structure of FIG. 1.For this reason the torque delivery elements in the FIG. 2 constructionhave been identified by the same reference numerals used in FIG.v 1although prime notations have been added.

Invthe FIG. 2 embodiment a cylinder drum 200 surrounds shaft 60 and issplined to it by means of a splined connection 202. The drum 200 definesa pair of annular cylinders 204 and 206. These receive, respectively,annular pistons 208 and 210. The outermost portion of the drum 200 isinternally splined at 212 and 214 to which pressure rings 216 and 218,respectively, are secured.

Gear 76' is provided with an externally splined clutch element 220 whichcarries internally splined clutch discs 222. These are situated adjacentexternally splined clutch discs 224 carried by the splinedportion 212.

Gear 72' is formed with an externally splined clutch element 226.Internally splined clutch discs 228 are carried by the element 226.These are situated adjacent externally f splined clutch discs 230carried by the internally splined portion 214 ofthe drum 200.

connected directly to the shaft 60. In this respect the clutch `shown inpart at 222 and 224 performs a function that is similar tol thesynchronizer clutch structure shown in part at 90 and 94. l

By pressurizing annular cylinder 206 the clutch shown in part at 228 and230 performs a function that is similar to the synchronizer clutchstructure shown in part at 88 and 92;

By pressurizing annular `cylinder 206 the clutch shown in part at 228and 230 establishes a direct connection between shaft 60' and gear 72. Y

A clutch structure substantially identical to the clutch structureassociated with gears 76 and 72' can be used also for connecting anddisconnecting gears 108 and '106' with respect to the shaft 60'.

The mode of operation and the shift sequence for the FIG. 2 constructionis the same as that described in reference FIG. l'. This will not berepeated here. Neither will a particular description of the fluidpressure operated disc clutch associated with the gears 108I and 106'.

FIG. 3 shows an embodiment in which the synchronizer clutches areremoved and replaced by simple sliding clutch sleeves which establishanddisestablish connections between gears 108", 106, 76" and 72" withrespect to the main shaft 60". In the FIG. 3 embodiment, the referencenumerals used to identify the torque delivery elements are the same asthose used to describe counterpart elements in the FIG. 1 construc tionalthough double prime notations have been added.

Clutch sleeve 126" in the FIG. 3 construction is a counterpart for thesleeve 126 in the FIG. 1 construction. It may be moved in either axialdirection to establish a driving connection between the gears 108'I and106" with respect to the shaft 60". The corresponding clutch sleeve forthe gears 76" and 72" is shown at 86". This forms a counterpart for thesleeve 86 in the FIG. l construction.

With the arrangements shown in FIG. 3, it is difficult to change ratioswhile the vehicle is moving, and in this respect the operatingperformance range for the vehicle under varying loads might be morelimited.

4 When employingthe basic gearing arrangement disclosed in FIG. l, 2 and3, itis possible to interchange one clutch arrangement for anotherdepending upon which operating conditions are present. But in each ofthe three embodiments it is possible to achieve four forward-drivingratios for each of` the operating ranges that are chosen, namely, thecreeper range, the transport range, the field range and the reverserange.

We Claim:

1. A multiple ratio power transmission mechanism adapted to delivertorque from an engine to a power output shaft comprising a main shaft,means for establishing a driving connection'between the engine and themain shaft, a plurality of torque delivery gears driven rotatably aboutthe axis of the main shaft, said gears having discrete pitch diametersthat are relatively evenly stepped from the maximum to the minimum, acountershaft mounted for rotation about its axis in parallel dispositionwith respect to the main shaft, a plurality of countershaft gearssecured drivably to said countershaft, each countershaft gear being inmeshing engagement with the first named torque delivery gears, finaldrive cluster gears mounted for rotation about an axis that is common tothe axis of said main shaft, a first output gear connected to saidoutput shaft, said first output gear being in meshing engagement withone of said'final drive cluster gears, a second output gear journaledfor rotation about the axis of the countershaft and situated in meshingengagement with a second of said final drive cluster gears, firstselectively engageable range selector clutch means for connectingselectively said output shaft to said countershaft and connecting saidcountershaft to said second output gear, and second selectivelyengageable range selector clutch means for connecting said final drivecluster gears to one of said main torque delivery gears.

2. A multiple ratio power transmission mechanism adapted to delivertorque from an engine to a power output shaft comprising a main shaft,means for establishing a driving connection between the engine and themain shaft, a plurality of torque delivery gears driven rotatably aboutthe axis of the -main shaft, said gears having discrete pitch diametersthat are relatively evenly stepped from the maximum to the minimum, acountershaft mounted for rotation about its axis in parallel dispositionwith respect to the main shaft, a plurality of coun- A tershaft gearssecured drivably to said countershaft, each countershaft gear being inmeshing engagement with the first named torque delivery gears, finaldrive cluster gears mounted for rotation about an axis that is common tothe axis of said main shaft, a first output gear connected to saidoutput shaft, said first output gear being in meshing engagement withone of said final drive cluster gears, a second output gear journaledfor rotation about the axis of the countershaft and situated in meshingengagement with a second of said final drive cluster gears, firstselectively engageable range selector clutch means for connectingselectively said output shaft to said countershaft and connecting saidcountershaft to said second output gear, second selectively engageablerange selector clutch means forlconnecting said final drive clustergears to one of said main torque delivery gears, a reverse gearjournaled for rotation about the axis of said final drive cluster gears,a second reverse gear drivably connected to said countershaft, and areverse pinion meshing with both of said reverse drive gears, saidsecond range selector clutch means being adapted to connect said firstreverse drive gear directly to said final drive cluster gear.

3. The combination as set forth in claim 1 wherein said torque deliverygears are four in number, first selectively engageable clutch means forconnecting separately the smallest and the nest smallest torque deliverygear to said main shaft and second selectively engageable clutch meansfor connecting selectively the third smallest and the fourth smallesttorque delivery gear to said main shaft whereby four forward drivingspeed ratios are available for each operating range selected by saidfirst and second range selector clutch means.

4. The combination as set forth in claim 2 wherein said ytorque deliverygears are four in number, first selectively engageable clutch means forconnecting separately the smallest and the next smallest main torquedelivery gear to said main driving speed ratios are available for eachoperating range selected by said first and second range selector clutchmeans.

